1. Field of the Invention
The present invention relates to a method for preventing or eliminating water-absorption whitening of a molded article containing an acrylonitrile polymer or copolymer.
2. Description of the Prior Art
An acrylonitrile polymer or copolymer has excellent gas-impermeability and transparency, and due to these properties it is used in the fields of receptacles for aerated drinks and casings for foods. In these fields, the receptacles and casings are exposed to an aqueous medium at high temperature for washing and sterilizing treatments. However, where the molded article of an acrylonitrile polymer or copolymer is exposed to an aqueous medium at a high temperature, there is the defect that transparency remarkably deteriorates, whereby appearance as a receptacle and casing is remarkably impaired.
Therefore, it has been strongly desired to obtain molded articles of acrylonitrile polymers or copolymers which do not remarkably deteriorate in transparency even though they are exposed to an aqueous medium at a high temperature.
It has further been desired to remove the water absorption whitening of molded articles of acrylonitrile polymers or copolymers to provide transparent molded articles thereof.